3rd generation partnership project (3GPP) long term evolution (LTE) is an improved version of a universal mobile telecommunication system (UMTS) and is introduced as the 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink, and uses single carrier-frequency division multiple access (SC-FDMA) in an uplink. The 3GPP LTE employs multiple input multiple output (MIMO) having up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-advanced (LTE-A) that is an evolution of the 3GPP LTE.
The Minimization of Driving Tests (MDT) is a test in which service providers perform tests for coverage optimization using terminals instead of using vehicles. Coverage is changed depending on the position of a base station, the deployment of surrounding buildings, and use environments of users. Accordingly, a service provider needs to perform a driving test periodically, and thus lots of costs and resources are consumed. The MDT is a test in which a service provider measures coverage using terminals.
The MDT may be divided into a logged MDT and an immediate MDT. In accordance with the logged MDT, a terminal performs MDT measurement and then transfers logged measurement to a network at a specific point of time. In accordance with the immediate MDT, a terminal performs MDT measurement and transfers the measurement to a network when a report condition is satisfied. In the logged MDT, MDT measurement is performed in RRC idle mode, but in the immediate MDT, MDT measurement is performed in RRC connected mode.
As measurement in various RRC modes, such as MDT, appears, it is necessary to configure a measurement configuration more flexibly.